4a^4-6a^3b^2-2a^2b^3 6a^3b^2c+12ab^3c-18abc^2 6m(n-m)^2-3mn(m-n) x(a-x)(a-y)-y(x-a)(y-a) 29×19.99+72×19.99+13×19.99-19.99×1.4
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/15 07:06:33
![4a^4-6a^3b^2-2a^2b^3 6a^3b^2c+12ab^3c-18abc^2 6m(n-m)^2-3mn(m-n) x(a-x)(a-y)-y(x-a)(y-a) 29×19.99+72×19.99+13×19.99-19.99×1.4](/uploads/image/z/356522-50-2.jpg?t=4a%5E4-6a%5E3b%5E2-2a%5E2b%5E3+6a%5E3b%5E2c%2B12ab%5E3c-18abc%5E2+6m%28n-m%29%5E2-3mn%28m-n%29+x%28a-x%29%28a-y%29-y%28x-a%29%28y-a%29+29%C3%9719.99%2B72%C3%9719.99%2B13%C3%9719.99-19.99%C3%971.4)
4a^4-6a^3b^2-2a^2b^3 6a^3b^2c+12ab^3c-18abc^2 6m(n-m)^2-3mn(m-n) x(a-x)(a-y)-y(x-a)(y-a) 29×19.99+72×19.99+13×19.99-19.99×1.4
4a^4-6a^3b^2-2a^2b^3 6a^3b^2c+12ab^3c-18abc^2 6m(n-m)^2-3mn(m-n)
x(a-x)(a-y)-y(x-a)(y-a) 29×19.99+72×19.99+13×19.99-19.99×1.4
4a^4-6a^3b^2-2a^2b^3 6a^3b^2c+12ab^3c-18abc^2 6m(n-m)^2-3mn(m-n) x(a-x)(a-y)-y(x-a)(y-a) 29×19.99+72×19.99+13×19.99-19.99×1.4
提取公因数2a^2得2a^2Xa^2-2a^2Xab^2-2a^2Xb^3=2a^2(a^2-ab^2-b^3)
提取公因数6abc得6abcXa^2b+6abcX2b^2-6abcX3c=6abc(a^2+2b^2-3c)
先将(n-m)化为-(m-n),再提取公因数-3m(m-n)得-3m(m-n)X2(n-m)-3m(m-n)Xn=-3m(m-n)(2n-2m+n)=-3m(m-n)(3n-2m)
先将(x-a)化为-(a-x)和将(y-a)化为-(a-y),再提取公因数(a-x)(a-y)得(a-x)(a-y)Xx-(a-x)(a-y)Xy=(a-x)(a-y)(x-y)
提取公因数19.99得19.99X(29+72+13-14)=1999.说明一下这里的1.4是14吧,是14的话才能将之合并为100这样的简单算术,否则这种简便方式无意义,原式则无简便方法.